Examples of the observed (in magenta) and modeled (black lines) SEDs of RS Oph at selected dates from the onset of its 2021 outburst. Definitions of the lines and symbols are shown in the keys (two top-left panels). The solid blue line represents the radiation of the warm WDP, while the dotted blue line (from day 5.416) represents the radiation of the hot WDP (see Section 3.2). The spectrum of the giant (in orange, panel (l)) was taken from A. Skopal (2015), recalculated for E_B−V = 0.69.